Ministers are prepared to tear up Britain’s foreign aid laws in a bid to cut waste, the International Development Secretary said last night.

Priti Patel said she was willing to unilaterally re-write the international rules governing aid spending if other countries refuse to accept Britain’s call for reform.

The rules ‘have not kept up with the changing world’ and were limiting the ability of the Government to make the most of the vast aid budget, she added.

The International Development (Official Development Assistance Target) Act, passed by the Coalition government, enshrines in law the target of spending 0.7 per cent of Britain’s income on aid, which has seen the aid budget balloon to more than £13billion

The Conservatives’ manifesto commits the party to keeping the target, despite public controversy.

But Miss Patel said ministers accepted some of the money could be better spent if the rules were relaxed to include things such as peacekeeping in countries where poverty is driven by conflict.

Previous British attempts to change the definition of aid have failed, and Miss Patel said ministers were now prepared to act unilaterally, saying Britain ‘can’t wait for the world to catch up’.

This would require a change in the law.

‘We are working with like-minded countries, like the Nordic countries and the Dutch in particular,’ she said. ‘There is a group of us discussing how we can lead reform in the way in which aid is spent.

‘We are world leaders when it comes to development. There are many countries that look to us.

‘We are in a very strong position to continue to show leadership in international development, through rule changes in my view. But if we don’t get everything we want we can’t wait for the world to catch up – we have to lead. We will continue to show leadership in development, either on our own or with our partners around the world.’

Britain is demanding a number of changes to the rules, which would make it possible to count some military activity towards the aid target.

Miss Patel said peacekeeping was ‘a classic example’ of the perverse nature of the rules. Currently it cannot be counted as aid spending, even though it is often an essential component of stabilising countries where conflict is driving humanitarian crises. Britain also wants to be able to use military assets such as ships and planes in delivering aid.

The UK is seeking a further change in the rules to allow the ‘pre-positioning’ of aid in countries including Haiti, which are regularly hit by natural disasters.

‘Believe it or not, you are not allowed to pre-position aid, even though you get better outcomes and save more lives if you do,’ Miss Patel said.

She has already given her department a shake-up since arriving last summer, including scrapping wasteful projects such as the funding for an African girl band dubbed the Ethiopian Spice Girls.

She acknowledged that David Cameron’s decision to implement the 0.7 per cent target at a time of austerity at home remained controversial with voters. But the International Development Secretary added that she was determined to drive through reforms to improve value for money and restore public confidence.

‘I get questioned about it a lot on the doorstep,’ she said.

‘But the public understand when I speak to them about the changes I am making, about how I’m not afraid to stop programmes I feel are not acting in our national interest or achieving the outcomes they should be – they accept we are making changes.

‘And they also understand that our work in places like Afghanistan is important for our national security.’